The invention relates to an information-carrying molded part containing one or more plastic layers, at least one of which bears an informative representation. In particular, a xe2x80x98molded partxe2x80x99 is understood to be a card, but it is not limited thereto. Known information-carrying cards are for example xe2x80x98smart cardsxe2x80x99, key cards, identification cards, telephone cards, credit cards or bankcards. Other moulded parts could be for example rods, strips, sepp keys, etcetera. An xe2x80x98informative representationxe2x80x99 is understood to be for example a text, a bar code or other optionally encrypted information, or a photo or an illustration. Also other, e.g. decorative representations are generally present on such parts, including company names or logos, background illustrations, etc.
Such information-carrying moulded parts have so far been made predominantly from polyvinylchloride compositions (PVC). This material is especially favoured in this application because it has a good stiffness and because it shows favourable printability, for example by using sublimation printing techniques. A major drawback of a PVC card, however, is that it shows limited resistance to bending and insufficient flexibility. Especially at comparatively low temperatures, a PVC card is very brittle and will easily break. PVC cards moreover often fail in those places where an electronic chip has been incorporated in the layer, or where letters or symbols have been embossed. At higher temperatures PVC cards generally display poor dimensional stability. An additional problem is that plasticisers used in softened PVC may migrate in and out of the PVC layer, as a result of which the properties of the moulded part may change in time and its life-time is limited. Another disadvantage is that representations printed on PVC have insufficient resistance to scratching. The aforementioned PVC problems are usually solved in practice by providing both sides of the PVC layer with further layers. EP-B-0430282, for example, describes an information-carrying card consisting of a stiff core layer which is essentially provided with outer layers, with in between the core and outer layer a layer of a thermoplastic elastomer for providing adhesion and for improving the flexibility and resistance to bending. In particular, mention is made of a card consisting of a PVC or polycarbonate (PC) core layer with polycarbonate outer layers and thermoplastic polyurethane (TPU) as adhesive layers. When PVC is used as the core layer the greatest disadvantage is not yet eliminated, and the cards have to be separately collected and processed after use, in order to prevent pollution of the environment with PVC. The embodiment with polycarbonate as a core layer presents the disadvantage that it is practically impossible to print on polycarbonate using sublimation techniques. Another disadvantage of the aforementioned cards is that they are fairly complex and hence expensive. EP-B-0430282 describes a PVC-free information-carrying card consisting of a core layer of a TPU with PC outer layers, but a disadvantage is that the TPU layer cannot be provided with information. Another disadvantage is that this structure can actually only be used in very thin cards. As TPU generally has a low crystallisation rate, a thicker TPU layer will acquire dimensional stability only after prolonged waiting times.